console 命令行工具 X clear

console

let canvas = document.createElement("canvas");
[canvas.width, canvas.height] = size;
document.body.appendChild(canvas);

let ctx = canvas.getContext("2d");

<!DOCTYPE html>
<html>

<head>
	<meta  charset="utf-8">
	<title>菜鸟教程(runoob.com)</title>
</head>

<body></body>

</html>

body {
    margin: 0;
    padding: 0;
}

canvas {
    border: 1px solid red;
}